Skin is the largest organ of the human body, representing approximately 16% of a person's total body weight. Because it interfaces with the environment, skin has an important function in body defense, acting as an anatomical barrier from pathogens and other environmental substances. Skin also provides a semi-permeable barrier that prevents excessive fluid loss while ensuring that essential nutrients are not washed out of the body. Other functions of skin include insulation, temperature regulation, and sensation. Skin tissue may be subject to many forms of damage, including burns, trauma, disease, and depigmentation (e.g., vitiligo).
Skin grafts are often used to repair such skin damage. Skin grafting is a surgical procedure in which a section of skin is removed from one area of a person's body (autograft), removed from another human source (allograft), or removed from another animal (xenograft), and transplanted to a recipient site of a patient, such as a wound site.
As with any surgical procedure, skin grafting involves certain risks. Complications may include graft failure, rejection of the skin graft, infections at donor or recipient site, or autograft donor sites oozing fluid and blood as they heal. Certain of these complications (e.g., graft failure and rejection of the skin graft) may be mitigated by using an autograft instead of an allograft or a xenograft.
A problem encountered when using an autograft is that skin is taken from another area of a person's body to produce the graft, resulting in trauma and wound generation at the donor site. Generally, the size of the graft matches the size of the recipient site, and thus a large recipient site requires removal of a large section of skin from a donor site, leading to increased pain and discomfort and longer healing time. Additionally, as the size of the section of skin removed from the donor site increases, so does the possibility of infection.
Moreover, skin grafts are often difficult to obtain due to the tendency of the skin layer being cut to curl or fold over onto itself or the surgical instrument (e.g., dermatome), thereby comprising the integrity of the graft and making it unsuitable for use. This folding/curling tendency is particularly problematic the thinner the layer is that is being obtained, such as the epidermal layer.
While techniques have been developed for obtaining smaller micrografts that can be transferred onto a substrate for expansion prior to transplantation, such micrografts tend to clump together or can flip or fold during cutting, thereby comprising the integrity of the micrograft such that it will not properly grow on the substrate. As such, multiple cutting attempts are often necessary before a suitable, planar graft or micrograft is obtained, thereby producing multiple wound sites, leading to extreme discomfort, longer healing time, and a greater risk of infection.
Harvesting of a skin graft may be accomplished by many different techniques, and the technique used will depend on the type of graft to be harvested. A common technique to harvest a skin graft includes suction blistering. Suction blistering typically involves a heat source to warm the skin which facilitates blister formation.
The heat source of a suction blistering device can become overheated and burn out, causing inconsistent blister formation and potential harm to the patient. Thus, there is a need for a skin graft harvesting device with design features that prevent the device from overheating.
Current skin graft harvesting devices do not include means to monitor the development of suction blisters formation. Without such means, the device may be applied for overly long periods of time causing excessive discomfort or harm to the patient, or insufficient periods of time for causing blister formation. Thus, there is a need for a skin graft harvesting device with design features that allow the user to visually monitor the development of suction blisters on a patient.
A common technique for harvesting a skin graft includes creating one or more suction blisters, cutting the blister, and transferring the blister to a substrate, for example Tegaderm®. If the substrate is not sufficiently contacted with the suction blister, the blister won't transfer and will thus be unusable. As such, there is a need for a skin grafting device with design features that ensure full contact between the substrate and suction blister.